This invention relates generally to methods and devices for treating incontinence and more specifically relates to an improved implantable artificial sphincter system for the control of excretory body passages.
The artificial sphincters for treating incontinence which are known or described in the art often employ a distally located fluid reservoir, usually of the balloon or bulb type, which in conjunction with one or more pumps serves to transfer fluid into or out of an inflatable cuff which is disposed about the body passageway to be occluded. When the cuff is inflated, the body passageway is occluded; when it is deflated the body passageway is opened and excretion occurs. It is also the norm that these basic components, that is, cuff, pump means, and reservoir are connected by means of lumens or fluid transmission passageways. Typically one fluid transmission passageway connects the cuff with the pump while a second transmission line connects the pump with the reservoir.
The location of the balloon type reservoirs are of particular concern in the known artificial sphincter systems. This is because reservoirs of this type tend to be rather large, particularly in proportion to the other components of the system. Because of their size, they are usually located in areas of the body which have room for such implantation. In most instances this will be in the abdomen. However, to implant bulb or balloon reservoirs in the abdomen necessitates rather complex surgery which can be debilitating particularly to the elderly. Moreover, abdominal surgery also incurs a fairly high risk of postoperative infection and is almost always rather long in duration, requiring a fairly lengthy postoperative healing period due to the trauma to which the body has been subjected. It is apparent that it would be highly desirable to avoid abdominal surgery and in general to reduce the complexity of the implantation procedures for artificial sphincters.
With known or described artificial sphincters it can also happen that high-intensity, short-duration (e.g., less than 5 minutes), stress-induced pressure "spikes", which occur, for example, as a consequence of the sudden onset of coughing or laughing, or other kind of stressful outburst, or even by the single act of suddenly lifting a heavy object, will often involuntarily induce the deflation of an occluding cuff. This can happen because these kinds of pressure "spikes" are often considerably above the threshold pressures necessary for the voluntary activation of the presently described sphincter systems. As a consequence, the "spike" can cause a sharp increase in pressure on the bladder and result in a surge of fluid under pressure downstream from the bladder (particularly if the latter is fairly full to begin with), which can then forcefully deflate the cuff (at least partially) and cause the urethra (or other excretory passage) to be opened and excretion to occur. This manifestation of incontinence, particularly where an artificial sphincter has been implanted, can be especially distressing and even demoralizing to an individual. It is thus also apparent that an artificial sphincter which would avoid this problem, i.e. which under these conditions would keep the cuff inflated and hence the urethra occluded, would also be very desirable.